Studor 20302 Maxi-Vent 3-Inch to 4-Inch Air Admittance Valve

Product Description Allow air to enter DWV systems to equalize pressure when water drains out of the system; eliminate the need for costly roof penetrations and vent piping. 1ATD5 vents up to 500 DFUs on a stack; 1ATD6 vents up to 160 DFUs on a branch and up to 24 DFUs on a stack. 15W940 has a replaceable cabon filter to reduce plumbing drainage system odors. From the Manufacturer Allow air to enter DWV systems to equalize pressure when water drains out of the system; eliminate the need for costly roof penetrations and vent piping. 1ATD5 vents up to 500 DFUs on a stack; 1ATD6 vents up to 160 DFUs on a branch and up to 24 DFUs on a stack. 15W940 has a replaceable cabon filter to reduce plumbing drainage system odors

• For use with: Venting Single Fixture, Individual Branch, Circuit Vent Or Stack Type Application Up To 500 DFU
• Material of Construction: ABS Plastic
• Standards: ASSE Performance Standard 10510 And 1051, NES-592, NSF Standard 14, IAPMO, File No C-3803, ITS Intertek Testing Services
• Package Dimensions : 5.5" L x 5.5" W x 8" H